In the container-fabrication art, it is desirable to provide containers with closures which can be easily opened and closed with one's bare hands, without necessitating the use of tools such as bottle openers or corkscrews. To this end, numerous different closures have been proposed.
One type of closure that is of particular interest is the so-called “flip-cap” closure (also commonly known as a “sport cap” closure), which comprises a cap attached to a base disposed on a mouth of the container by a hinge. When the closure is opened, the cap rotates about an axis of the hinge situated substantially tangent to a rim of the base, and swings upward and away from the mouth of the container.
Such flip-cap closures are particularly advantageous in that they require no tools to open and are generally easy to use by those possessing minimal dexterity or grip strength without sacrificing sealing performance. Moreover, the hinge structure ensures that the cap remains retained with the container at all times, thereby reducing the risk of choking and minimizing the proliferation of litter.
With regard to flip-cap closures, it is particularly desirable in to provide a flip-cap closure which presents as little obstruction as possible to the dispensing and/or consumption of the product held within the container. Specifically, it is desirable to provide a flip-cap closure configured such that, when fully opened, the cap of the closure is as far removed from the opening of the closure as possible, so as to prevent contact between the cap and the face of the consumer when the latter is drinking directly from the container. Moreover, to maximize ease of use, the cap should open in a smooth and predictable manner.
To this end, there exist in the prior art attempts to maximize the range of motion in a flip-cap closure. In particular, it has long been known in the art to provide a hinge in the form of a long, freely-flexible strip of material, which connects the base of the closure to the cap at a point at or near the top of the cap. While this can achieve a great deal of deflection, this is disadvantageous in that a large portion of the hinge protrudes when the closure is disposed in the closed position.
Other closures exist which minimize the amount by which the hinge protrudes from the closure when closed. In particular, the document WO 99/64312 A1 (WO'312) describes a flip-cap closure with a connecting member. In WO'312, the connecting member consists of a cap connected to a base by means of two hinges connected in series. When the cap is disposed on the base to seal the closure, the protrusion of the hinge from the cap is minimal.
However, the structure of the hinge and the cap substantially block any further rotation, limiting the range of motion of the closure. However, the closure of WO'312 can still come into contact with the face of the user as he or she drinks from the container, because even at a full 180° deflection, the cap of WO'312 is no further away from the end of the container than when it is in the fully-closed position. The closure of WO'312 is insufficient to resolve the problems known in the art.
There is thus a need for a flip-cap type closure wherein the protrusion of the hinge in the closed position is minimized, but also in which the cap can be opened to a high degree of deflection.